The IBM VM/SP line of products permits a processor to emulate a plurality of dedicated processors. Each of the users of these emulated processors appear to have all of the facilities of the processor at his disposal for computation. A control program (CP) controls the resources of the real system processor to provide for many virtual machines (VM) each of which appears as an individual processor. A conversational monitor system (CMS) is a second layer of programming protocol which provides a wide range of terminal user dialogue and time sharing services. Using CMS, each of the VM users can create and manage files and compile test and run application programs supplied by each VM user.
The operation of these VM/SP systems requires that common data be available for the control program (CP). Included among these is a requirement that there be system name tables (SNT) which are made up of saved, named object definitions, such as Named Saved Systems (NSS) or Shared Segments (SS). These saved named object definitions are kept in the control program (CP) portion of a direct access storage device (DASD).
In creating these definitions, a macro is utilized to format the data and make it part of the host module (DMKSNT, DMKSYS or DMKBOX). These modules in turn are part of the (CP) nucleus.
In order to modify or change such a CP nucleus, a new nucleus must be generated and formatted such that a subsequent initial program load of the control program will load each of the new and existing nucleus named objects into the control program system memory.
With current VM/SP operating systems, the addition or replacement of these saved named objects necessarily causes a disruption of processing that is experienced by all VM users of the system. Replacement can only be accomplished by a total shutdown of the VM system, followed by a system initial program load, wherein the CP program can retrieve and store in memory the new parameters. This necessarily results in a disruption to each of the VM users.
An additional complication in modifying or "tailoring" the CP nucleus is encountered wherein several VM systems comprise a single large installation of VM systems. These systems may be located in different national regions and may support very different types of application programs. For instance, it would not be unusual for a large company to have VM installations in different countries which, although including many common files to its CMS system, may have a different set of named saved objects resulting in a different CP nucleus for each system. Thus, it is difficult to administer the changes to such a CP nucleus from a central location when the two nuclei are not identical. Forming a single nucleus having parameters sufficient for two different system nucleus requirements adds complexity to the management of the DASD for these saved, named objects.
It is an object of this invention to provide a method for reconfiguring a control program nucleus with minimum disruption for system users.
It is a more specific object of this invention to provide for key system configuration definitions and named saved object definitions in an override source file on a CMS-managed mini-disk.
It is yet another object of this invention to permit the parameters stored in the override source file of a mini-disk to be transferred to the control program without the necessity of a nucleus regeneration or a system IPL for the control program.
It is a further object of this invention to provide the imbedding of files unique to one VM system nucleus with common files used in a multiplicity of VM systems.
It is an additional object of this invention to include with system object definitions sufficient information so that the control program can, while validating individual object definition data, indicate with an error message the particular object definition data and its location on a CMS file, producing an error.